The preservation potential of terrestrial biogeographic patterns

Abstract

Extinction events in the geological past are similar to the present-day biodiversity crisis in that they have a pronounced biogeography, producing dramatic changes in the spatial distributions of species. Reconstructing palaeobiogeographic patterns from fossils therefore allows us to examine the long-term processes governing the formation of regional biotas, and potentially helps build spatially explicit models for future biodiversity loss. However, the extent to which biogeographic patterns can be preserved in the fossil record is not well understood. Here, we perform a suite of simulations based on the present-day distribution of North American mammals, aimed at quantifying the preservation potential of beta diversity and spatial richness patterns over extinction events of varying intensities, and after applying a stepped series of taphonomic filters. We show that taphonomic biases related to body size are the biggest barrier to reconstructing biogeographic patterns over extinction events, but that these may be compensated for by both the small mammal record preserved in bird castings, as well as range expansion in surviving species. Overall, our results suggest that the preservation potential of biogeographic patterns is surprisingly high, and thus that the fossil record represents an invaluable dataset recording the changing spatial distribution of biota over key intervals in Earth History.

Size-driven preservational and macroecological biases in the latest Maastrichtian terrestrial vertebrate assemblages of North America

“…On the one hand, the pattern of dinosaur size distributions can be interpreted as a real biological phenomenon; the result of intrinsic ecological or physiological differences between mammals and dinosaurs, such as through the competitive exclusion of small-bodied dinosaurs by juveniles of larger species (Richmond 1965; Varricchio 2011; Codron et al 2012, 2013; O'Gorman and Hone 2013; Schroeder et al 2021). On the other hand, a negatively skewed body-size distribution pattern may result from large taphonomic and/or collection biases toward large-bodied taxa (Behrensmeyer et al 1979; Farlow 1993; Peczkis 1994; Farlow et al 1995; Brown et al 2013a,b; Benson 2018; Darroch et al 2021). Such a bias was detected and quantified in the Dinosaur Park Formation (Brown et al 2013a,b), is supported by contrasting body-size distributions between Recent and fossil (last 10 Ma) mammals (Benson 2018), and contrasts with typically positively skewed size distributions in Lagerstätte-type deposits of the Jehol (Benson 2018).…”

Response to Kozlovet al.: Inaccurate estimation of biases in herbarium specimen data

“…Finally, we suggest that Kozlov et al ’s conclusion that herbarium specimens may serve as “distorting mirrors” is unjustified because it reaches beyond the limited quantifications of bias in their study. Like any historical reconstruction from fossils 15 or modern specimens 11 , it is important to identify potential sources of bias in the data. However, a bias or source of noise along any one axes does not preclude the value of these data for exploring variation across other axes.…”

Geography of Indian Butterflies: Patterns Revealed by Checklists of Federal States

“…In an ideal world, large-scale analyses of species distribution patterns would be based on data obtained using a standard survey of equally-sized spatial units, typically grids; this allows for direct comparisons among taxa, countries, continents and biogeographical realms [ 1 , 2 , 3 ]. For obvious reasons, data of such quality are available only for a few superbly studied taxa [ 4 , 5 , 6 , 7 ], usually for selections from much-studied countries and regions, typically situated in the Global North [ 8 , 9 , 10 , 11 , 12 ]. Methods to overcome these limitations include the use of point records transferred to grid systems and modeling species distributions for non-surveyed locations [ 8 , 11 , 13 ], ideally accounting for variations in survey efforts [ 14 ].…”